USRP2 1pps synchronization delay

We are trying to determine how much delay there is between the 1pps
pulse and when the samples come out properly time tagged. Using a GPS
timing receiver we connected up the 10MHz clock and 1pps to the USRP2.
The software is set up to reset on the next 1pps pulse. With a GPS
software receiver we determined that there is a delay of 3 - 6
microseconds which curiously was 3 with a smaller decimation and 6 at a
higher decimation. We’ve checked over the setup and can’t find any
reason for this. Does anyone have any ideas?

Thanks,

Cliff

Does this describe what you are seeing?

http://www.mail-archive.com/[email protected]/msg26328.html